Polymer compositions containing as antioxidants substituted hexahydropyrimidines

ABSTRACT

This invention relates to diamines prepared by condensing cyclohexanone, or derivatives thereof, with ammonia to yield tetrahydropyrimidines, which can be reduced to hexahydropyrimidines, whose pyrimidine ring can be broken to yield diamines having one primary amino group, which primary group can be reacted with a carbonyl to yield Schiff base imines, which Schiff base imines can be reduced to N-subsituted amino groups. The two amino groups of the reduced Schiff base can be bridged by reaction with an aldehyde to form N,N&#39;-disubstituted hexahydropyrimidines. 
     This invention also relates to the use of these products as antioxidants.

This is a Division of Application Ser. No. 815,886, filed July 15, 1977,by Neil E. S. Thompson, now U.S. Pat. No. 4,129,597, for Amino Compoundsand Use Thereof as Antioxidants.

In Ser. No. 292,494 filed on Sept. 27, 1972 now U.S. Pat. No. 4,085,104there is described and claimed substituted 2,3,4,5-tetrahydropyrimidines(THP) ##STR1## which are prepared by the following reactions: (1) Thereaction of a carbonyl compound (ketone or aldehyde) with (NH₃ or NH₄OH) and a sulfur-containing catalyst.

(2) The reaction of an α,β-unsaturated ketone and a carbonyl compoundand NH₃ (or NH₄ OH) without a catalyst.

(3) Reaction of an α,β-unsaturated ketone, a 1-amino-alcohol and NH₃ (orNH₄ OH) without a catalyst.

In the above formula, R₁, R₂, R₃, R₄, R₅ and R₆, which may be the sameor different, are hydrogen or substituted group such as alkyl, aryl,cycloalkyl, alkaryl, aralkyl, heterocyclic, substituted derivativesthereof, etc. In addition R groups may be joined in a cyclicconfiguration which makes the THP structure a part of the substitutedgroup.

Alkyl includes methyl, ethyl, propyl, butyl, amyl, hexyl, heptyl, octyl,nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl,hexadecyl, heptadecyl, octadecyl, escosyl, docosyl, etc. for examplehaving about 1-25 or more carbons such as from about 1-18 carbons, butpreferably about 1-12 carbons. The term "alkyl" also includes isomers ofthe straight chain where branching occurs.

Cycloalkyl includes cyclopentyl, cyclohexyl, etc. and derivativesthereof such as alkyl-cyclohexyl, dialkylcyclohexyl, etc.

Aryl, alkaryl and aralkyl, including phenyl, alkylphenyl,polyalkylphenyl, chlorophenyl, alkoxyphenyl, naphthyl, alkylnapthyl,etc., benzyl, substituted benzyl, etc.

The joining of the R groups into a ring structure include thosestructures derived from reactants of the general formula ##STR2## suchas cyclohexanone, cyclopentanone, substituted derivatives thereof suchas alkyl-cyclohexanone, dialkyl-cyclohexanone.

Ser. No. 597,564 filed July 21, 1975 discloses that 2,2-disubstitutedderivatives of Formula I can be converted to linear diamines such asN-substituted-2,4-diamino-2-substituted pentanes by hydrogenation.

It was further disclosed in Ser. No. 597,564 that such reaction occursonly with the 2,2-di-substituted tetrahydropyrimidines. Where the2,2-di-substitution is not present, the corresponding cyclichexahydropyrimidines are formed instead of the linear diamines.

Ser. No. 597,564 also disclosed further that a compound of Formula IIcan be converted to an amine-imine by reacting with a carbonyl compound.

Ser. No. 597,564 also disclosed the amine-imine can be converted to thecorresponding N,N'-substituted diamines by hydrogenation.

These reactions may be summarized as follows: ##STR3## or morespecifically as follows: ##STR4##

Although the above reactions are illustrated with the trimethyltetrahydropyrimidine, the methyl groups may be replaced with othergroups such as for example hydrogen, higher alkyls, aryls, cycloalkyls,etc.

The hydrogenation reaction is carried out in the presence of ahydrogenation catalyst such as palladium, platinum, nickel, etc.; at asuitable temperature, for example from ambient to 200° C. or higher, butpreferably 50°-150° C.; at pressures sufficient to contain hydrogen inthe reaction vessel, such as about 10-2000 psi, or higher but preferablyabout 200-1000 psi; for a sufficient period of time for the reaction totake place such as from about 10 minutes to 24 hrs. or longer,preferably from about 1/2 hr. to 6 hrs.; in solvents which do notinterfere with the catalyst, reactants, or products such as water,alcohol, hydrocarbons, esters, etc.

In addition, reduction can be effected with compositions which onreaction yield hydrogen such as metal hydrides, etc.

The linear amine resulting from hydrogenation is then reacted with acarbonyl compound of the formula ##STR5## which is either an aldehyde ora ketone.

The preparation of the imine compound is conventional. For example thereaction can be carried out by heating the amine with substantiallystoichiometric amounts of the carbonyl compound under dehydratingconditions, i.e., 1:1 molar ratio, for example by the use of anazeotroping agent.

The imine compound resulting from the carbonyl reaction can be furtherreduced in the manner of Step 1 to yield the substituted diamine.

In the above formula, R₇ and R₈, which may be the same or different, arehydrogen or substituted group such as alkyl, aryl, cycloalkyl, alkaryl,aralkyl, heterocyclic, substituted derivatives thereof, etc. In additionR groups may be joined in a cyclic configuration.

Alkyl includes methyl, ethyl, propyl, butyl, amyl, hexyl, heptyl, octyl,nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl,hexadecyl, heptadecyl, octadecyl, escosyl, docosyl, etc., for examplehaving about 1-25 or more carbons such as from about 1-18 carbons, butpreferably about 1-12 carbons. The term "alkyl" also includes isomers ofthe straight chain where branching occurs.

Cycloalkyl includes cyclopentyl, cyclohexyl, etc. and derivativesthereof such as alkyl-cyclohexyl, dialkyl-cyclohexyl, etc.

Aryl, alkaryl and aralkyl include phenyl, alkylphenyl, polyalkylphenyl,chlorophenyl, alkoxyphenyl, naphthyl, alkylnaphthyl, etc., benzyl,substituted benzyl, etc.

The joining of the R groups into a ring structure include thosestructures derived from reactants of the general formula ##STR6## suchas cyclohexanone, cyclopentanone, substituted derivatives thereof suchas alkyl-cyclohexanone, dialkyl-cyclohexanone.

The following examples are presented for purposes of illustration andnot of limitation.

EXAMPLE 1 N-Cyclohexyl-2,4-diamino-2-methylpentane

In a 1 liter stirred autoclave was placed 95 g of2,2-pentamethylene-4,4,6-trimethyl-2,3,4,5-tetrahydropyrimidine, 200 cc.of methanol and 6 g of 5% Pt/C catalyst. The autoclave was pressurizedwith 400 psi of hydrogen gas and the mixture heated for 75 minutes at75°-80° C. while a pressure of 400-800 psi was maintained. The reactionproduct was removed through an internal filter leaving the catalystbehind. After removal of the solvent, there was isolated 95 g ofN-cyclohexyl 2,4-diamino-2-methylpentane.

The analytical data were consistent with the assigned structure ##STR7##

Anal. calced for C₁₂ H₂₆ N₂ ; N, 14.14: Found N, 13.98.

EXAMPLE 2 N-Cyclohexyl, N'-isobutyl 2,4-diamino-2-methylpentane

A sample of 50 g of N-cyclohexyl-2,4-diamino-2-methylpentane and 18.7 gof isobutyraldehyde in 50 cc of benzene was refluxed under azeotropicalconditions for 1 hr. The benzene was removed under diminished pressureto yield 67 g of product. The product was dissolved in 200 cc ofmethanol and 9.6 g of sodium boronhydride was slowly added withstirring. After the reaction was completed, the solvent was removedunder diminished pressure. To the resulting product was added water andthe organic layer was separated. The aqueous layer was extracted withether and the ethereal solution combined with the organic layer. Afterremoval of the ether under diminished pressure the product was distilledunder diminished pressure to yield 60 g of N-Cyclohexyl, N'-isobutyl2,4-diamino-2-methylpentane, b₀.6 =98° C.

Anal. calcd. for C₁₆ H₃₂ N₂ ; N, 11.11: Found; N, 11.01.

The analytical data were consistent with the assigned structure ##STR8##

EXAMPLE 3

N-Cyclohexyl, N' isobutyl 2,4-diamino-2-methylpentane and 18.7 g ofisobutyraldehyde in 50 cc of benzene was refluxed under azeotropicalconditions for 1 hour. After removal of the solvent, the product wasdissolved in 100 cc of methanol and placed with 2 g of a 10% Pt/Ccatalyst in an autoclave. The reaction was pressurized with 400 psi ofhydrogen and the mixture was heated with stirring for 3 hrs. at 75°-80°C. After removal of the catalyst by filtration, the methanol was removedunder diminished pressure to yield 67 g of N-Cyclohexyl, N'-isobutyl2,4-diamino-2-methylpentane, identical in all respects to the productisolated as described in example 2.

EXAMPLE 4 N-Cyclohexyl, N'-isobutyl 2,4-diamino-2-methylpentane

In a 1 liter stirred autoclave was placed 95 g of 2,2-pentamethylene4,4,6-trimethyl 2,3,4,5-tetrahydropyrimidine, 200 cc of methanol and 6 gof 5% Pt/C catalyst. The mixture was hydrogenated with stirring for 60minutes at 75°-80° C. and 400-800 psi of hydrogen. To the mixture wasadded 39 g of isobutyraldehyde and hydrogenation was continued for 3hrs. at 75°-80° C. and 400-800 psi of hydrogen pressure. The catalystwas removed and the mixture evaporated under diminished pressure, toyield 116 g of N-cyclohexyl, N'-isobutyl 2,4-diamino-2-methylpentane,identical in all respects to the product isolated as described inexample 2.

The following 2,4-diamino-2-methylpentanes were prepared, according tothe methods described in examples 1-4. The results are summarized inTable I.

                  Table I:                                                        ______________________________________                                        General Structure:                                                             ##STR9##                                                                     Ex.                                                                           No.  R.sub.1                                                                              R.sub.2 R.sub.3   R.sub.4                                         ______________________________________                                         5   CH.sub.3                                                                             CH.sub.3                                                                              --        --*                                              6   CH.sub.3                                                                             CH.sub.3                                                                              H         CH(CH.sub.3).sub.2                               7   CH.sub.3                                                                             CH.sub.3                                                                              H         CH.sub.2CH.sub.2CH.sub.3                         8   CH.sub.3                                                                             CH.sub.3                                                                              H         Phenyl                                           9   CH.sub.3                                                                             CH.sub.3                                                                              CH.sub.2CH.sub.2CH(CH.sub.3)CH.sub.2CH.sub.2              10   CH.sub.3                                                                             C.sub.2 H.sub.5                                                                       --        --*                                             11   CH.sub.3                                                                             C.sub.2 H.sub.5                                                                       H         CH(CH.sub.3).sub.2                              12   (CH.sub.2).sub.5                                                                         H           C.sub.2 H.sub.5                                   13   (CH.sub.2).sub.5                                                                         H           CH.sub.2CH.sub.2CH.sub.3                          14   (CH.sub.2).sub.5                                                                         (CH.sub.2).sub.5                                              15   (CH.sub.2).sub.5                                                                         H           Phenyl                                            16   (CH.sub.2).sub.5                                                                         H           CH(C.sub.2 H.sub.5).sub.2                         17   (CH.sub.2).sub.5                                                                         H           CH.sub.3                                          18   (CH.sub.2).sub.5                                                                         CH.sub.2CH(CH.sub.3)CH.sub.2CH.sub.2CH.sub.2                  19   (CH.sub.2).sub.5                                                                         CH.sub.2CH.sub.2CH(CH.sub.3)CH.sub.2CH.sub.2                  ______________________________________                                         ##STR10##                                                                

The novel compounds of this invention are analogous to those of thegenera formulas of Ser. No. 597,564. Thus, the formulas of Ser. No.597,564 are modified as follows: ##STR11## so that the dotted linesindicate cyclic structures as follows: ##STR12## In the case of##STR13## the modification is as follows: ##STR14## to yield: ##STR15##

The two amino groups can be bridged by reaction with an aldehyde such asformaldehyde so that the above formula becomes ##STR16##

In the above formulae, indicates the moiety of a cycloalkyl group or asubstituted cycloalkyl group for example substituted with an alkyl,halo, alkoxy, phenyl, etc. group. The preferred cycloalkyl group iscyclohexyl.

Compounds analogous to those described in Ser. No. 597,564 have beenprepared. These are summarized by the following.

(1.) Cyclohexanone condensed with ammonia to yield tetrahydropyrimide asfollows: ##STR17## (2.) Reduction of tetrahydropyrimidines tohexahydropyrimiines as follows: ##STR18## (3.) Reductive scission ofhexahydropyrimidines to form linear diamines as follows: ##STR19## (4.)Reductive alkylation by formation of the Schiff base imine and reductionthereof as follows: ##STR20## (5.) Formation of Hexahydropyrimides bybridging the two amino groups with an aldehyde as follows: ##STR21##

The following examples are presented for purposes of illustration andnot of limitation.

EXAMPLE 1A 2,2,4,4-Dipentamethylene 5,6-tetramethylene2,3,4,5-tetrahydropyrimidine

To a mixture of 294 grams of cyclohexanone and 5 grams of ammoniumchloride placed in a pressure reactor was added over a 3/4 hour period38.8 grams of ammonia gas. After the addition was completed, the mixturewas stirred for 5 hours at ambient temperature. The product was taken upin toluene and the aqueous phase which separated was discarded. Thetoluene solution was evaporated under diminished pressure to yield 268grams of2,2,4,4-dipentamethylene-5,6-tetramethylene-2,3,4,5-tetrahydropyrimidine;infrared spectrum, 6.02μ (C═N); C¹³ n.m.r. spectrum: solvent CDCl₃,reference T.M.S.: ##STR22##

EXAMPLE 2A 2-(1'-aminocyclohexyl)-Dicyclohexylamine

A sample of 30 grams of the product described in example 1A, 300 cc. ofmethanol and 2 grams of a 5% Pt/C catalyst were placed in a 1 l.autoclave. To the mixture was added 800 psi of hydrogen gas and themixture was heated with stirring for 21/2 hours at 75°-80° C. Afterremoval of the catalyst by filtration and the solvent by evaporationthere was isolated 29 grams of 2-(1'-aminocyclohexyl)-dicyclohexylamine:C¹³ n.m.r. spectrum ##STR23##

EXAMPLE 3A 2,2,4,4-Dipentamethylene-5,6-tetramethylenehexahydropyrimidine

A mixture of 294 grams of cyclohexanone and 51 grams of 90% formic acidwas placed in a pressure reactor. To the mixture was added with coolingand stirring 58.6 grams of ammonia gas over a 1/2 hour period. Themixture was stirred for 18 hours at ambient temperature. The resultingproduct was subjected to a vacuum (25 mm Hg) at 60° C. and thedistillate 18 grams of unreacted cyclohexanone and water was discarded.The product was further heated for 3 hours at 120°-125° C. The resultingproduct 237.6 grams (86%) was identified as2,2,4,4,-dipentamethylene-5,6-tetramethylene hexahydropyrimidine. b₀.5153°-155° C.

Anal. Cal.ed for C₁₈ H₃₂ N₂ ; C, 78.20; H, 11.67; N, 10.14: Found C,77.94; H, 11.74; N, 10.08. ##STR24##

EXAMPLE 4A 2-(1'-aminocyclohexyl)-Dicyclohexylamine

A sample of 30 grams of the product described in example 3A, 300 cc ofmethanol and 2 grams of a 5% Pt/C catalyst was placed in an autoclave.The mixture was hydrogenated for 3 hours at 800-1,000 psi of hydrogen.After removal of the catalyst and solvent, there was isolated 30 gramsof 2-(1'-aminocyclohexyl)-dicyclohexylamine, identical in all respectsto the product described in Example 2A. ##STR25##

EXAMPLE 5A N-Cyclohexyl N'-isoburyl 1,2-tetramethylene3,3-pentamethylene 1,3-diaminopropane

A sample of 28 grams of the product described in Example 2A, 7.5 gramsof isobutyraldehyde and 300 cc of methanol was placed in a 1 l.autoclave. To the mixture was added 2 grams of a 5% Pt/C catalyst andthe mixture was hydrogenated for 11/2 hours at 600-800 psi of hydrogen.After removal of the catalyst and solvent, there was isolated 33 gramsof a product with spectral characteristics in agreement with thestructure shown: ##STR26##

EXAMPLE 6A 1-Cyclohexyl 3-isobutyl 4,4-pentamethylene 5,6-tetramethylenehexahydropyrimidine

A mixture of 17 grams of the product described in Example 5A, 1.5 gramsof paraformaldehyde and 100 grams of toluene were refluxed underazeotropical conditions for 18 hours. After removal of the toluene underdiminished pressure, there was isolated 18 grams of a product withspectral characteristics in agreement with the structure shown:##STR27##

I have discovered that the compositions of this invention preserve andprotect organic material subject to deterioration due to oxidation andother influences. They are particularly effective in rubber goods wherethey function as antioxidants. Accordingly, this invention comprisesmethods and compositions involving the use of such compositions asanti-oxidants for the preservation of organic substances which tend todeteriorate in the presence of oxygen including such materials as fishoil, linseed oil, tung oil, carotene, lubricating oils, animal fats,soaps and, especially, rubbery unsaturated organic polymeric materials.

The term "rubbery unsaturated organic polymeric material" is employed toinclude all natural and synthetic unsaturated rubbery polymericmaterials and especially those which may be considered to be polymers ofconjugated dienes. Examples of such rubbery materials include thevarious natural crude rubbers (which are regarded as naturally-occurringisoprene polymers) and such synthetic rubber as polymers of conjugateddienes such as butadiene-1,3, isoprene, 2-methyl butadiene-1,3 and otherbutadiene-1,3 hydrocarbons, chloroprene, cyano butadiene-1,3 etc., aswell as copolymers of these conjugated dienes with each other or withother unsaturated compounds copolymerizable, therewith such as styrene,chlorostyrenes, isobutylene, acrylonitrile, methacrylonitrile, acrylicand methacrylic acids, alkyl acrylates and methacrylates, vinylidenechloride, vinyl pyridine, etc.

These compositions, as antioxidants, are incorporated, in any desiredmanner, with the oxidizable material to be protected. In general, about0.25 to 10% of weight of antioxidant based on total weight of materialis generally sufficient to obtain adequate protection from oxidation,such as about 0.25 to 5%, for example, from about 0.5 to 4%, butpreferably from about 1 to 3%.

The effectiveness of the compounds of the invention as antioxidants isdemonstrated by subjecting rubber samples containing them to acceleratedheat aging (Test Tube Method) and comparing the relative deteriorationof the samples compared to the deterioration shown in similar samplescontaining no antioxidant (blank) and samples containing threecommercially available antioxidants. The three commercial antioxidantsare identified as:

(a.) Agerite Stalite S--a general purpose antioxidant recommended forall elastomers

(b.) Agerite superlite--the preferred antioxidant for non-staining andnon-discoloring rubber compounding

(c.) Agerite Resin D--extensively used antioxidant to protect naturaland synthetic rubbers against heat and oxidation under most severeservice conditions.

The polymer in which these tests were conducted was a natural rubberstock which was formulated and cured as sheets in a conventional manner.The natural rubber composition was prepared in accordance with thefollowing recipe:

    ______________________________________                                        Components          Parts by Weight                                           ______________________________________                                        Smoked Sheet        100.00                                                    Stearic Acid        2.00                                                      Zinc Oxide          5.00                                                      Titanium Oxide      50.00                                                     Altax               1.00                                                      Methyl Tuads        0.10                                                      Sulfur              2.75                                                      ______________________________________                                    

1.5 part by weight of the selected antioxidant was added to the abovemixture to provide a batch. A series of samples containing the selectedantioxidant was prepared from the batch. A second series of samples wasalso prepared which contained no antioxidant, to serve as blanks. Allthe samples were first cured, their tensile properties determined (ASTMD412), and then they were subjected to accelerated heat aging (T.T.Method) at 212° F. for 96 hours (ASTM D865). Their tensile propertiesafter the heat aging treatment was measured. The results are shown inthe following table.

    __________________________________________________________________________    Test Data                                                                                       Agerite                                                                            Agerite                                                                            Agerite                                                                            Exam-                                                                             Exam-                                                  Blank                                                                             Stalite S                                                                          Superlite                                                                          Resin D                                                                            ple 5A                                                                            ple 6A                                   __________________________________________________________________________    A.                                                                              Unaged Physicals:                                                             ASTM D412                                                                     Elongation, %                                                                             570 670  610  650  530 530                                        300% Modulus, MPa                                                                         3.6 3.2  3.2  3.5  5.5 5.9                                        Tensile Strength, MPa                                                                     21.8                                                                              26.9 21.4 26.2 23.6                                                                              23.9                                     B.                                                                              Air-Aged-48 Hours                                                             212° F. ASTM D865                                                      Elongation, %                                                                             270 330  400  400  450 460                                        % Change    -53%                                                                              -51% -53% -38% -15%                                                                              -13%                                       300% Modulus, MPa                                                                         --  7.9  6.5  10.5 5.2 5.4                                        % Change    --  +147%                                                                              +103%                                                                              +200%                                                                              - 5%                                                                              - 8%                                       Tensile Strength, MPa                                                                     3.4 8.4  11.4 18.6 14.5                                                                              16.1                                       % Change    -84%                                                                              -69% -47% -29% -38%                                                                              -33%                                     C.                                                                              Air-Aged-96 Hours                                                             at 212° F. ASTM D865                                                   Elongation, %                                                                             180 140  200  330  450 340                                        % Change    - 68%                                                                             -79% -67% -49% -15%                                                                              -36%                                       300% Modulus, MPa                                                                         --  --   --   8.3  4.4 4.7                                        % Change    --  --   --   +137%                                                                              -20%                                                                              -20%                                       Tensile Strength, MPa                                                                     2.2 2.5  3.0  9.1  9.7 5.8                                        % Change    -90%                                                                              -91% -86% -65% -59%                                                                              -76%                                     __________________________________________________________________________

The above results clearly demonstrate the effective antioxidantproperties of the compounds of the invention in protecting naturalrubber vulcanizates against heat aging deterioration.

The antioxidant compounds of the invention are also non-staining andnon-discoloring, which is a very useful and important property. Adisadvantage of many of the more effective antioxidants is staining anddiscoloration--i.e., a darkening in color of the vulcanized rubber inwhich they are used. This effect is particularly noticeable uponexposure to light. Articles originally of one color may take on variousshades according to the amount of exposure. Staining is masked in blankarticles, so the most potent antioxidants may be used, even though theyare of the staining type. In many cases, for example in rubber flooring,light colors with good aging properties are essential. To meet suchrequirements non-staining and non-discoloring antioxidants have beendeveloped. Until recently these were of low efficiency and only relativenon-staining. Within the last few years however, intensive research bymanufacturers of antioxidants has led to the introduction of new types,which combine efficiency and the absence of staining. The followingtests illustrate the non-staining and non-discoloring characteristics ofthe products of this invention.

Contact and Migration Staining

ASTM--D925--Methods A and B on white acrylic enamel, 48 hours at 140° F.Specimens exposed 10 inches from R. S. bulb.

    __________________________________________________________________________    Exposure Time     Example                                                                              Example                                                                              Agerite                                       (Hours)    Blank  5A     6A     Resin D                                       __________________________________________________________________________    Staining after 24 hrs.                                                                   No migration                                                                         No migration                                                                         No migration                                                                         No migration                                  Staining after 48 hrs.                                                                   No migration                                                                         No migration                                                                         No migration                                                                         Some migration                                           No contact                                                                           No contact                                                                           No contact                                                                           No contact                                    __________________________________________________________________________

I claim:
 1. An unsaturated polymer composition containing antioxidantamounts of a compound of the formula ##STR28## where the ##STR29##moiety is the residue of an aldehyde or ketone in which the twounsatisfied valences attached to the indicated carbon of said moiety areattached to the same oxygen atom and R₇ and R₈ together with the carbonto which they are joined may form a cyclohexane or cyclopentane ring oralkyl substituted derivative thereof and together with the carbon orcarbon atoms to which it is shown attached indicates a cyclopentyl orcyclohexyl cycloalkyl ring or such a cycloalkyl ring substituted byalkyl, halo, alkoxy, or phenyl.
 2. An unsaturated polymer compositioncontaining antioxidant amounts of the compound of claim 1 where R₇ isalkyl and R₈ is hydrogen or alkyl.
 3. An unsaturated polymer compositioncontaining antioxidant amounts of the compound of claim 2 where R₈ ishydrogen and R₇ is ##STR30##
 4. An unsaturated polymer compositioncontaining anti-oxidant amounts of the compound of claim 1 where thecycloalkyl rings are cyclohexyl rings.
 5. An unsaturated polymercomposition containing anti-oxidant amounts of the compound of claim 2where the cycloalkyl rings are cyclohexyl rings.
 6. An unsaturatedpolymer composition containing anti-oxidant amounts of the compound ofclaim 3 where the cycloalkyl rings are cyclohexyl rings.
 7. Anunsaturated polymer composition containing anti-oxidant amounts of thecompound of claim 1 having the formula ##STR31##
 8. A rubberyunsaturated organic polymeric material containing antioxidant amounts ofthe compound of claim
 1. 9. A rubbery polymer of butadiene-1,3containing an anti-oxidant amount of the compound of claim
 7. 10. Anatural rubber composition containing an antioxidant amount of thecompound of claim
 7. 11. The composition of claim 2 in which alkylrepresents alkyl of 1 to 25 carbon atoms.